diff --git a/client/app/scripts/reducers/__tests__/root-test.js b/client/app/scripts/reducers/__tests__/root-test.js
index 86b440b54..f4e80a6c8 100644
--- a/client/app/scripts/reducers/__tests__/root-test.js
+++ b/client/app/scripts/reducers/__tests__/root-test.js
@@ -500,4 +500,29 @@ describe('RootReducer', () => {
     nextState = reducer(nextState, {type: ActionTypes.SET_RECEIVED_NODES_DELTA});
     expect(nextState.get('gridMode')).toBe(true);
   });
+  it('cleans up old adjacencies', () => {
+    // Add some nodes
+    const action1 = {
+      type: ActionTypes.RECEIVE_NODES_DELTA,
+      delta: { add: [{ id: 'n1' }, { id: 'n2' }] }
+    };
+    // Show nodes as connected
+    const action2 = {
+      type: ActionTypes.RECEIVE_NODES_DELTA,
+      delta: {
+        update: [{ id: 'n1', adjacency: ['n2'] }]
+      }
+    };
+    // Remove the connection
+    const action3 = {
+      type: ActionTypes.RECEIVE_NODES_DELTA,
+      delta: {
+        update: [{ id: 'n1' }]
+      }
+    };
+    let nextState = reducer(initialState, action1);
+    nextState = reducer(nextState, action2);
+    nextState = reducer(nextState, action3);
+    expect(nextState.getIn(['nodes', 'n1', 'adjacency'])).toBeFalsy();
+  });
 });
diff --git a/client/app/scripts/reducers/root.js b/client/app/scripts/reducers/root.js
index 3248c2eb6..81d686b8b 100644
--- a/client/app/scripts/reducers/root.js
+++ b/client/app/scripts/reducers/root.js
@@ -553,7 +553,7 @@ export function rootReducer(state = initialState, action) {
       // update existing nodes
       each(action.delta.update, (node) => {
         if (state.hasIn(['nodes', node.id])) {
-          state = state.updateIn(['nodes', node.id], n => n.merge(fromJS(node)));
+          state = state.setIn(['nodes', node.id], fromJS(node));
         }
       });